Prevalence of African Horse Sickness Virus Antibodies in Horses and Selected Wildlife in Four Geographical Regions of Nigeria

Abstract

African horse sickness (AHS) is a severe, infectious arthropod‐borne disease of equids caused by the AHS virus (AHSV). It is endemic in Sub‐Saharan Africa, and several sporadic outbreaks of the disease have been reported in Nigeria in the past 5 decades. Following a recent outbreak of the disease in Lagos State, this study was conducted to investigate the prevalence of (AHSV) antibodies in apparently healthy horses and some selected wildlife sampled in four geographical regions of Nigeria. Using a competitive enzyme‐linked immunosorbent assay, 575 serum samples collected from horses in five locations, namely Abuja ( n = 220), Enugu ( n = 69), Oyo ( n = 64), Plateau ( n = 145) and Yobe ( n = 77), were screened for anti‐AHSV antibodies. In addition, we screened 134 wildlife, consisting of rodents, bats, and birds. The results obtained revealed an overall seroprevalence rate of 89.9% ( n = 517) in horses, with the highest (100%) and lowest (75%) recorded in Enugu State, southeastern Nigeria, and Oyo State, southwestern Nigeria, respectively. There was a 0% prevalence amongst the wildlife examined. This high seroprevalence rate in horses shows that AHS is widespread among the horse population in different regions of Nigeria, suggesting significant exposure to the virus. In addition, the high AHS seroprevalence suggests endemicity of the disease in Nigeria, which could be attributed to Culicoides vector activities. Although we could not distinguish between antibodies due to natural infection and those induced by vaccination, our findings emphasize the need for continuous surveillance of AHS in horses in Nigeria to track the possible evolution of the virus in the country and aid the formulation of effective prevention and control strategies against the disease.